Method of treating wool



Patented Apr. 12, 1949 METHOD OF TREATING WOOL Daniel Frishman, Washington, D. 0., and Milton Harris, Bethesda, Md., assignors, by mesne assignments, to Harris Research Laboratories, a

partnership No Drawing. Application April 4, 1946,

Serial No. 659,664

Claims.

1 This invention relates to a method of treating wool and particularly to a method for rendering .wool, including wool-like animal fibers, and

fabrics made therefrom, resistant to shrinking.

A principal object of the invention is the provision of an improved method for rendering woolen materials resistant to shrinking.

Another object of the invention is the provision of a. method for increasing the resistance of woolen materials to shrinking without deleteriously affecting the strength, color, feel and other desirable properties of the wool.

A further object of the invention is the provision of a method for improving the properties of woolen materials.

We have found that by treating woolen materials with active halogen oxidizing agents of relatively high strength for a very short period of time, it is possible to greatly improve the resistance of the materials to shrinkage in laundering and other textile treating operations without impairing the desirable properties of the wool. In some cases, the properties of wool fabrics, such as color and strength, are improved by the treatment of the invention. In particular, the treatment of the invention usually has a wholly unexpected bleaching effect when applied to undyed woolen materials.

Typically, the woolen material is contacted with a solution of active halogen oxidizing agent, preferably of a strength equivalent to from about 1% to about 6% of available chlorine, and there- 'after, after an interval of from about one to about sixty seconds, the oxidation agent is eliminated from the woolen material by contacting the wool with an excess of an antichlor, such as sodium bisulfite or hydrogen peroxide, or by thoroughly rinsing the woolen material with water.

Advantageously, the woolen material is treated with the oxidizing agent in the presence of a substantial amount, for example, from 0.1% to 1.0%, of a wetting agent resistant to the oxidizillg agent. Suitable wetting agents are sodium salts of sulfuric acid esters of higher secondary alcohols, such as the material commercially known as Tergitol 4, fatty acid esters of polyhydric alcohols, such as the material commercially known as Tween 20, and highly sulfonated fatty esters, such as the material commercially known as Tetranol.

The treatment may be effected at any pH in.

The temperature of the treatment is not critmaterial.

ical and may vary from 0 C. to 35 C. Operation at ambient temperatures ranging around 20' C. is particularly suitable.

In general, the higher the temperature and the lower the pH, the shorter should be the time of treatment to obtain optimum results. At temperatures of about 20 C. and within the pH range of 7.5 to 9, contact with the oxidizing solution for a time within the range of 2 to 10 sec.- onds, will give satisfactory results with most woolen materials.

It is our belief that the advantageous results obtained by the method of the invention are largely due to the rapid surface action of the oxidizing agent on the wool fibers with a minimum of penetration into the fiber substance Woolen materials in all forms and constr tions may be treated by the method of the sin;- vention, including raw stock, top, yarn and woven or knitted fabrics. Mixed yarns and fabricscof wool with other fibers, such as cotton or rayon, may also be treated. The materials maybe treated before dyeing or, if the dyes are resistant to the oxidizing agent used, dyed materials may be treated. v

The method of the invention is particularly adapted to being carried out as a continuous process, resulting in substantial economies in mill operation. Advantageously, the material tofj-rbe treated is passed through an oxidizing solution, such as a solution of a hypochlorite, in a padding machine from which is passes through squeeze rollers adjusted to leave in the material about of the solution based on the weight of the From the squeeze rollers the material passes through a pan of antichlor and is then thoroughly rinsed with running water; or the material may pass directly from the squeeterollers to the water rinse.

invention to different types of woolen materials:

Example 1.- White flannel shirting (10.5 oz.)

A solution containing 3% of available chlorine at' pH 8.5 is prepared by dissolving 1% of borax in water, adding commercial sodium hypochlorite solution (13-15% available chlorine), adding 0.8% of Tergitol 4, and adjusting to pH 8.5 with 2N sulfuric acid.

The shirting material is passed through the solution in a padding machine at 20 C. and thence to squeeze rolls adjusted to leave 60% of the solution on the weight of the material at a speed such that the total time from contact with the solution to the squeeze rolls is 2.3 seconds. From the squeeze rolls the material is passed directly into a 1% solution of sodium bisulfite and then is rinsed with running water.

In an accelerated laundering test in which the untreated fabric shows an area shrinkage of 39%, the treated fabric shows a shrinkage of only 1%.

Erample 2.Wool blanketing (21.5 02.)

21.5 oz. woolen blanket material is treated like the flannel shirting in Example 1 except that the hypochlorite solution is adjusted to pH 9 and the time of contact with the solution is 3 seconds.

The area shrinkage of the treated'material is nil while the untreated blanketing shrinks 19% in the same laundering test.

Example 3.Knitted woolen skirting Knitted woolen shirting is treated in the same way as the flannel shirting in Example 1.

The treated fabric shows no shrinkage in the accelerated laundering testwhile the untreated fabric shrinks 67% in area.

Example 4.-50% cotton-50% woolen knit underwear fabricv This mixed wool-cotton knitted fabric is treated as in Example 1 at pH 8 for 3.5 seconds. The area shrinkage of the untreated fabric is 19% and the shrinkage of the treated fabric 3%.

Example 5.50% rayon-50% worsted fabric This mixed wool-rayon fabric is treated as in Example 1 with a solution made up to 3.5% available chlorine with high test calcium hypochlorite containing about 70% available chlorine and ad- Justed to pH 9 with hydrochloric acid. The solution contained 0.4% of Tween 20. The time of treatment is 3.5 seconds. i

The treated fabric shows no shrinkage during laundering while the untreated fabric shrinks 66% in area.

Example 6.Wool top Wool top is treated as in Example 1 with a solution made up as in Example 5 to 3% available chlorine with high test calcium hypochlorite, at pH 9 for 3.5 seconds.

When samples of the treated and untreated top are tumbled for five minutes in soap solution with several rubber stoppers, the untreated sample forms a hard felted mass, while the treated sample remains stringy and can readily be separated into the fibers.

Example 7.White flannel skirting (10.5 oz.)

The shirting is wetted with water containing about .8% Tergitol 4 and is then passed, as in Example 1, through a solution made up to 6% available chlorine with commercial sodium hypo- '4 with the use of inexpensive readily available materials. It will further be seen that the conditions of treatment are subject to a substantial range of variation without departing from the principles of the invention-as defined in the fol? lowing claims.

We claim:

1. A method of treating woolen materials which comprises contacting the material with an alkaline hypochlorite solution containing from about 1% to about 6% available chlorine, leased on the solution for a period of from about one to about sixty seconds at a pH of about 7.5 to about 9 and immediately thereafter eliminating the hypochlorite from the material.

2. A method of treating woolen materials which comprises contacting the material with a hypochlorite solution containing from about 1% to about 6% available chlorine based onv the solution for a period of from about two to about ten seconds at a pH of about 7.5 to about 9 and immediately thereafter eliminating the hypochlorite from the material.

3. A method of treating woolen materials which comprises contacting the material with a hypochlorite solution containing from about 1% to about 6% available chlorine based on the solution and from about 0.1% to about 1% of a wetting agent resistant to hypochlorite for a period of from about two to about ten seconds at a pH of about 7.5 to about 9 and. immediately thereafter eliminating the hypochlorite from the material.

4. A method of treating woolen materials which comprises contacting the materialwith an alkaline hypochlorite solution containing from about 1% to about 6% available chlorine based on the solution for a period of from about two to about ten seconds ata pH of about 7.5 to about 9 and immediately thereafter eliminating the hypochlorite from the material by treating the material with an antichlor.

5. A method.of treating woolen materials to impart resistance to shrinkage which comprises contacting the material with a hypochlorite solution containing from about 1% to about 6% available chlorine based on the solution for a period of from about two to about ten seconds at a pH of about 7.5 to about 9 at a temperature not exceeding about C. in the presence of a wetting agent and immediately thereafter treating the material with an antichlor.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Trotman Jan. 13, 1925 Smith Nov. 11, 1930 Cowley Feb. 26, 1946 FOREIGN PATENTS OTHER REFERENCES Mueller, "Chlorage de la Laine," Rev. gen. mat. colon, vol. 41, 1937, pages 78-86.

6 Number Number Certificate of Correction Patent No. 2,466,695. April 12, 1949.

DANIEL FRISHMAN ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 11, claim 1, for the word leased read based;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case 1n the Patent Oflioe.

Signed and sealed this 6th day of September, A. D. 1949.

THoMAs F. MURPHY, Assistant G'ommz'ssioner of Patents. 

